Machining apparatus often incorporate what are referred to as “guide bars” which are used to support structures that guide the workpiece relative to the cutting tool or bit. In a table-saw, for example, the guide bar is commonly used to support a fence, or a miter gage. The guide bars are typically of rectangular cross-section, and slide in correspondingly shaped slots that are machined or cast into the table of the apparatus.
Table-saws typically have tables that are only about 27″ square. It is therefore difficult to use such table-saws to saw standard 4×8 sheets of material (e.g., plywood), and so it is often necessary to provide additional tables, adjacent the table-saw, to support the overhanging material. Even with this additional support, however, there remains a problem associated with, at least, standard 4×8 sheets of plywood, which is that they are not sufficiently square (i.e., the edges are not close enough to being perpendicular) and the use of, e.g., a fence or miter gage is needed to rectify this.
In response to this problem, table-saw guide bars have been used to support what are referred to as “sleds” that provide a larger table area that can be translated. However, the guide bars remain supported only within the footprint provided by the table, which is insufficient to provide for accurate control of the movement of the sled over the relatively large excursions required. The present invention addresses the need for a simple and inexpensive solution to this problem.